Secondary airflow distribution for a display case

ABSTRACT

A display case cools and displays products. A first fan system circulates cool air through the display case. The cool air is directed downwardly along a front of the display case to form a primary air curtain. A second fan system circulates ambient air to generate a secondary air curtain. The secondary air curtain is located between the primary air curtain and the outside environment, trapping the primary air curtain near an interior display volume of the display case. Each end of the second fan system is several inches shorter than the display case to allow for case to case attachment. The second fan system includes a louver near each of the side walls and a front of the second fan system. Each louver includes a plurality of slanted panels. The louvers direct the ambient air towards the side walls of the display case to improve the secondary discharge air velocity in a front corner area of the display case.

BACKGROUND OF THE INVENTION

The present invention relates generally to a display case including afan system having deflectors that direct ambient air towards side wallsof the display case to improve the discharge air velocity of the ambientair in a front corner area of the display case.

Refrigerated food and beverage display cases (or merchandisers) arecommonly used in grocery stores or supermarkets to cool refrigeratedproducts and present the products to customers in an appealing manner. Afirst fan system generates a first air curtain that cools the productsin the display case. A second fan system generates a second air curtainthat reduces the entrapment of ambient air in the display case.

Several display cases can be attached side by side. The second fansystem is several inches shorter than the display case at each side toallow for case to case attachment. A drawback to prior display cases isthat the flow of ambient air is restricted towards the side walls of thedisplay case, reducing the supply and velocity of ambient air at bothends of the display case. The ratio of the primary discharge airvelocity to the secondary discharge air velocity ratio should bemaintained in an acceptable range along an entire length of the displaycase or weak spots can occur where the velocity ratio is not correct andlocal infiltration can occur. If the desired ratio is not maintained,condensation can form at top front corners of the interior displayvolume of the display case. For example, the secondary discharge airvelocity of the ambient air directed towards the side walls of thedisplay case could be 40 to 50% of the desired secondary discharge airvelocity.

Hence, there is need in the art for a display case including a fansystem having deflectors that direct ambient air towards side walls ofthe display case to improve the discharge air velocity of the ambientair in a front corner area of the display case and that overcomes thedrawbacks and shortcomings of the prior art.

SUMMARY OF THE INVENTION

A display case or merchandiser cools and displays products. A first fansystem located at a bottom of the display case circulates cool airthrough the display case. An evaporator coil cools the air, and thecooled air is directed upwardly through a rear duct along a rear of thedisplay case. After traveling through an upper conduit at a top of thedisplay case, the air is directly through a primary discharge grill anddownwardly over a front of the display case to form a primary aircurtain.

A second fan system circulates ambient air to generate a secondary aircurtain. A fan draws ambient air into the secondary air system. The airflows through a space and is then directed through a conduit. Theambient air is directed through a secondary discharge grill anddownwardly to form the secondary air curtain. The secondary air curtainis located between the primary air curtain and the outside environment,trapping the primary air curtain near an interior display volume of thedisplay case.

Each end of the second fan system is several inches shorter than thedisplay case to allow for case to case attachment. The second fan systemincludes a louver near each of the side walls and a front of the secondfan system. Each louver includes a plurality of slanted panels. Thelouvers direct the ambient air towards the side walls of the displaycase to improve the secondary discharge air velocity in a front cornerarea of the display case.

These and other features of the present invention will be bestunderstood from the following specification and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The various features and advantages of the invention will becomeapparent to those skilled in the art from the following detaileddescription of the currently preferred embodiment. The drawings thataccompany the detailed description can be briefly described as follows:

FIG. 1 schematically illustrates a side view of a display case of thepresent invention;

FIG. 2 schematically illustrates a side view of a fan system of thedisplay case;

FIG. 3 schematically illustrates a front view of the display case;

FIG. 4 schematically illustrates two display cases attached together;

FIG. 5 schematically illustrates an upper view of a louver; and

FIG. 6 schematically illustrates a side view of the louver.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 illustrates a supermarket display case 10 or merchandiser. Thedisplay case 10 cools or refrigerates products 12 and presents theproducts 12 to customers in an appealing manner. The products 12 can beproduce, dairy products, meat products, or any other refrigeratedproduct. The display case 10 includes shelves 36 that hold the products12.

The display case 10 includes a first fan system 14 that circulates coolair through the display case 10 to cool the products 12 to a desiredtemperature. The display case 10 includes a fan blade 84 and a fan motor86 located in a lower section 16 of the display case 10 that draws airthrough a return grille 18. The air is forced through an evaporator coil20 (part of a refrigeration system including a compressor, not shown)that cools the air to a desired temperature. The cooled air flowsupwardly through a rear duct 22. Part of the air moving up the rear duct22 also diffuses into an interior display volume 30 of the display case10 through holes 38 in a rear duct panel 40 to help refrigerate theproducts 12.

The air then flows to a front 82 of the display case 10 through an upperconduit 24. The air flows through a perforated plate 34 and isdischarged downwardly and vertically towards a floor 32 through aprimary discharge grille 26 (such as a honeycomb) to form a primary aircurtain 28. The primary air curtain 28 cools the products 12 in thedisplay case 10, separating the interior display volume 30 from theambient air external to the display case 10. The air then flows throughthe return grille 18, completing the air circulation cycle.

As further shown in FIG. 2, the display case 10 further includes asecond fan system 42 located above a top 50 of the display case 10 thatdraws in ambient air and generates a secondary air curtain 48 that isdischarged downwardly and vertically. A panel 68 separates the primaryair curtain 28 from the secondary air curtain 48 in the second fansystem 42. The temperature of the ambient air is greater than thetemperature of the air cooled by the evaporator coil 20.

The secondary air curtain 48 flows next to the primary air curtain 28 ata desired velocity and/or at a different angle than the primary aircurtain 28 to provide an optimized combined airflow and to improve theoverall efficiency of the air curtain system of the display case 10. Inone example, the primary air curtain 28 and the secondary air curtain 48are separated by an angle of approximately 15 to 35°. The secondary aircurtain 48 is located between the primary air curtain 28 and the outsideenvironment, trapping the primary air curtain 28 near the interiordisplay volume 30 of the display case 10. The secondary air curtain 48reduces the entrapment of the higher temperature and higher humidityambient air into the display case 10, reducing the load requirementbecause there is less heat and mass transfer into the display case 10.

A fan motor 44 and a fan blade 46 draw ambient air into the second fansystem 42 through an opening 52. The ambient air travels through a space54 along a path A above a panel 58. The air then flows though a conduit56 along a path B below the panel 58 towards the front 82 of the displaycase 10. The air then flows through an opening 60 and into a space 62along a path C. The air then travels through a perforated plate 64 andthen discharges through a secondary discharge grille 66 (such as ahoneycomb), forming the secondary air curtain 48.

FIG. 3 shows a front view of the display case 10 and the second fansystem 42. The air drawn into the display case 10 through the opening 52flows through the space 54 in a direction substantially into the pagealong the path A. In one example, the air flows entirely along a lengthY of the second fan system 42. The air then flows through the conduit 56in a direction substantially out of the page along the path B. In oneexample, the air flows along the entire length Y of the second fansystem 42. Finally, the air flows downwardly and vertically along thepath C.

The display case 10 has a length X extending between side walls 70. Thesecond fan system 42 has the length Y that extends between side walls72. The length Y of the second fan system 42 is shorter than the lengthX of the display case 10 by a length 2Z. That is, each side wall 72 ofthe second fan system 42 is spaced apart from each side wall 70 of thedisplay case 10 by a length Z. In one example, the length X is 144inches, the length Y is 136 inches, and the length Z is 4 inches. Thatis, each end wall 72 of the second fan system 42 is recessed from one ofthe side walls 70 of the display case 10 by 4 inches. Therefore, the airflowing along paths A, B and C is not directed towards the side walls 70of the display case 10.

As shown in FIG. 4, two or more display cases 10 can be attached to forma display case lineup, allowing for a continuous product display thatcan be longer than the length X of the display case 10. There is nopartition between the individual display cases 10, and thereforeproducts 12 off similar usage or temperature can be displayed. Thelength Y of the second fan system 42 is shorter than the length X of thedisplay case 10 to provide an access area 74 that allows display cases10 to be connected. In one example, the display cases 10 are attachedwith a bolt 88 that passes through a bracket 92 in the side wall 70 ofeach the display case 10. In one example, the access area 74 is locatedat the top front area of the display case 10. The display cases 10 areattached at the top front area and in other areas to form a sealedconnection. For example, the other areas can be a top back area and abottom of the display cases 10.

Returning to FIG. 3, the panel 58 includes a deflector near each sidewall 72 of the second fan system 42. In one example, the deflector is alouver 76. That is, each display case 10 includes two louvers 76. Eachlouver 76 is near a front 90 of the second fan system 42 and onlyextends partially along a depth W of the second fan system 42.

Each louver 76 allows some of the pressurized air in the space 54 to bedirected toward one of the side walls 70 of the display case 10downwardly and vertically along a path D, improving airflow at the sidewalls 70 of the display case 10. The louvers 76 direct a small portionof the ambient air of the second fan system 42 into a front corner areaof the secondary discharge grille 66 and towards the side walls 70 ofthe display case 10. The airflow along the path D is directed generallyunder the access area 74. The secondary discharge air velocity at theside walls 70 of the display case 10 can be increased to a desired airvelocity, resulting in a consistent primary air discharge velocity tosecondary discharge air velocity ratio throughout the length X of thedisplay case 10. Weak spots in the secondary air curtain 48 can beeliminated that could allow outside air to migrate into the display case10 and form condensation inside a front corner area of the interiordisplay volume 30 of the display case 10.

FIGS. 5 and 6 illustrate the louver 76. Each louver 76 includes aplurality of slanted panels 78 and openings 80 defined between each ofthe slanted panels 78. The slanted panels 78 are angled so that theambient air is directed towards the side walls 70 of the display case10. In one example, the louvers 76 are stamped in the panel 58.

The foregoing description is only exemplary of the principles of theinvention. Many modifications and variations of the present inventionare possible in light of the above teachings. The preferred embodimentsof this invention have been disclosed, however, so that one of ordinaryskill in the art would recognize that certain modifications would comewithin the scope of this invention. It is, therefore, to be understoodthat within the scope of the appended claims, the invention may bepracticed otherwise than as specifically described. For that reason thefollowing claims should be studied to determine the true scope andcontent of this invention.

1. A refrigerated case comprising: a display area having an interiorcompartment and side walls; a first fan system that directs air along afront of the refrigerated case to form a first air curtain; and a secondfan system that directs ambient air along the front of the refrigeratedcase to form a second air curtain, wherein the first air curtain isbetween the interior compartment and the second air curtain, and thesecond fan system includes at least one deflector that directs at leastsome of the ambient air towards one of the side walls of therefrigerated case.
 2. The refrigerated case as recited in claim 1wherein the first fan system includes a first fan and a first motorlocated in a lower portion of the refrigerated case and an evaporatorcoil to cool the air.
 3. The refrigerated case as recited in claim 1wherein the air is directed downwardly to form the first air curtain. 4.The refrigerated case as recited in claim 1 wherein the second fansystem is located above the interior compartment.
 5. The refrigeratedcase as recited in claim 1 wherein the second fan system includes asecond fan and a second motor, wherein the second fan draws the ambientair into the second fan system.
 6. The refrigerated case as recited inclaim 1 further including a panel, wherein the ambient air flows underthe panel and is directed downwardly to form the second air curtain. 7.The refrigerated case as recited in claim 6 wherein the panel includesthe at least one deflector.
 8. The refrigerated case as recited in claim6 wherein the at least one deflector includes two deflectors and thepanel includes the two deflectors, wherein each of the two deflectors islocated near the one of the side walls.
 9. The refrigerated case asrecited in claim 1 wherein the at least one deflector includes aplurality of slanted panels each separated by a slot that allow theambient air to flow through the at least one deflector and towards theone of the side walls.
 10. The refrigerated case as recited in claim 1wherein the display area has a display area length and the second fansystem has a fan length, and the display area length is greater than thefan length.
 11. The refrigerated case as recited in claim 1 wherein theat least one deflector is located near the front of the refrigeratedcase.
 12. The refrigerated case as recited in claim 1 wherein the atleast one deflector extends only partially along a depth of the secondfan system.
 13. The refrigerated case as recited in claim 1 wherein theat least one deflector is at least one louver.
 14. A refrigerated casecomprising: a display area having an interior compartment and sidewalls; a first fan system that directs air along a front of the case toform a first air curtain, wherein the first fan system includes a firstfan and a first motor located in a lower portion of the refrigeratedcase and an evaporator coil to cool the air; and a second fan systemthat directs ambient air along the front of the case to form a secondair curtain, wherein the second fan system includes a second fan and asecond motor, wherein the second fan draws the ambient air into thesecond fan system, the first air curtain is between the interiorcompartment and the second air curtain, and the second fan systemincludes at least one deflector that directs at least some of theambient air towards one of the side walls of the refrigerated case. 15.The refrigerated case as recited in claim 14 further including a panel,wherein the air is directed downwardly to form the first air curtain andthe ambient air flows under the panel and is directed downwardly to formthe second air curtain.
 16. The refrigerated case as recited in claim 14wherein the at least one deflector includes two deflectors and the panelincludes the two deflectors, wherein each of the two deflectors islocated near the one of the side walls.
 17. The refrigerated case asrecited in claim 14 wherein the at least one deflector includes aplurality of slanted panels each separated by a slot that allow theambient air to flow through the at least one deflector and towards theone of the side walls.
 18. The refrigerated case as recited in claim 14wherein the at least one deflector is at least one louver.
 19. A methodof cooling a refrigerated case, the method comprising the steps of:directing air along a front of the refrigerated case to form a first aircurtain; directing ambient air along the front of the refrigerated caseto form a second air curtain, wherein the first air curtain is betweenan interior compartment and the second air curtain; and directing atleast some of the ambient air towards at least one side wall of therefrigerated case.